netdev - Re: [PATCH net-next 00/10] Call skb_metadata_set when skb->data points past metadata

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260112190856.3ff91f8d@kernel.org>
Date: Mon, 12 Jan 2026 19:08:56 -0800
From: Jakub Kicinski <kuba@...nel.org>
To: Jakub Sitnicki <jakub@...udflare.com>
Cc: netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>, Eric
 Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>, Simon
 Horman <horms@...nel.org>, Michael Chan <michael.chan@...adcom.com>, Pavan
 Chebbi <pavan.chebbi@...adcom.com>, Andrew Lunn <andrew+netdev@...n.ch>,
 Tony Nguyen <anthony.l.nguyen@...el.com>, Przemek Kitszel
 <przemyslaw.kitszel@...el.com>, Saeed Mahameed <saeedm@...dia.com>, Leon
 Romanovsky <leon@...nel.org>, Tariq Toukan <tariqt@...dia.com>, Mark Bloch
 <mbloch@...dia.com>, Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann
 <daniel@...earbox.net>, Jesper Dangaard Brouer <hawk@...nel.org>, John
 Fastabend <john.fastabend@...il.com>, Stanislav Fomichev <sdf@...ichev.me>,
 intel-wired-lan@...ts.osuosl.org, bpf@...r.kernel.org,
 kernel-team@...udflare.com
Subject: Re: [PATCH net-next 00/10] Call skb_metadata_set when skb->data
 points past metadata

On Sat, 10 Jan 2026 22:05:14 +0100 Jakub Sitnicki wrote:
> This series is split out of [1] following discussion with Jakub.
> 
> To copy XDP metadata into an skb extension when skb_metadata_set() is
> called, we need to locate the metadata contents.

"When skb_metadata_set() is called"? I think that may cause perf
regressions unless we merge major optimizations at the same time?
Should we defer touching the drivers until we have a PoC and some
idea whether allocating the extension right away is manageable or 
we are better off doing it via a kfunc in TC (after GRO)?
To be clear putting the metadata in an extension right away would
indeed be much cleaner, just not sure how much of the perf hit we 
can optimize away..